Functions

Function Headers

A function header names the return type, function name, and parameter list.

header `int square(int value)` is the function header.
definition The function definition combines the header with the body that runs.

Function Headers

value
function_prototypes.c
Replay: real traced execution (multi-file project)
#include <stdio.h>

int square(int value) {
    return value * value;
}

int main(void) {
    int value = 4;
    int result = square(value);

    printf("square=%d\n", result);
    return 0;
}

#include <stdio.h>

int square(int value) {
    return value * value;
}

int main(void) {
    int value = 6;
    int result = square(value);

    printf("square=%d\n", result);
    return 0;
}

#include <stdio.h>

int square(int value) {
    return value * value;
}

int main(void) {
    int value = 9;
    int result = square(value);

    printf("square=%d\n", result);
    return 0;
}

  1. value ← 4

    7int main(void) {8    int value→ 4 = 4; //@value=6, 99    int result = square(value4);

  2. int square(int value)

    3int square(int value4) {4    return value4 * value;5}

  3. result ← 16

    8    int value = 4; //@value=6, 99    int result→ 16 = square(value4);1011    printf("square=%d\n", result16);12    return 0;13}
    outputsquare=16

  1. value ← 6

    7int main(void) {8    int value→ 6 = 6;9    int result = square(value6);

  2. int square(int value)

    3int square(int value6) {4    return value6 * value;5}

  3. result ← 36

    8    int value = 6;9    int result→ 36 = square(value6);1011    printf("square=%d\n", result36);12    return 0;13}
    outputsquare=36

  1. value ← 9

    7int main(void) {8    int value→ 9 = 9;9    int result = square(value9);

  2. int square(int value)

    3int square(int value9) {4    return value9 * value;5}

  3. result ← 81

    8    int value = 9;9    int result→ 81 = square(value9);1011    printf("square=%d\n", result81);12    return 0;13}
    outputsquare=81